1. Field of the Invention
The present invention relates to a muffler of a compressor and particularly to a muffler of a compressor in which flow of refrigerant gas is smooth and pulsation flow can be decreased.
2. Description of the Background Art
Generally, a muffler applied to a compressor is installed at a suction side or discharge side of a compressor so as to attenuate suction noise occurred when sucking fluid or discharge noise occurred when discharging fluid.
A muffler installed at the suction side is called as a suction muffler and a muffler installed at the discharge side is called as a discharge muffler.
A suction muffler and a discharge muffler decrease pulsation phenomenon occurred periodically when sucking and discharging fluid.
Also, a suction muffler and a discharge muffler attenuate compressor noise by blocking valve noise occurred when sucking and discharging fluid and flow noise of fluid.
Hereinafter, a suction muffler applied to a reciprocating type compressor will be described.
FIG. 1 is a longitudinal cross-sectional view showing an example of a reciprocating compressor having a conventional muffler of a compressor.
As shown in FIG. 1, a conventional reciprocating compressor is comprised of a casing 1 which is filled with oil, a electric motor unit which is installed in the inner lower part of the compressor to generate driving force by power supply from the outside of the compressor, and a compression unit which is installed in the upper part of the electric motor unit receiving driving force of the electric motor unit to suck and compress gas.
The compression unit includes a frame 2 which is fixed inside of the casing 1 in the horizontal direction, a cylinder 3 which is fixed at one side of the frame 2, a driving shaft 5 which penetrates the center of the frame 2 and is pressed-fitted to a rotor 4B of the electric motor unit, a connecting rod 6 which is connected with the upper eccentric part of the driving shaft 5 to change a rotational motion to a reciprocating motion, a piston 7 which is connected with the connecting rod 6 and which performs a reciprocating motion in the cylinder 3, a valve assembly 8 assembled to the cylinder 3 to control the suction and discharge of refrigerant gas, a head cover 9 which is combined to the valve assembly 8 having a certain discharge space (DS), a suction muffler 10 which is connected to one side of the head cover 9 so that the muffler 10 is connected to the valve assembly 8 and a discharge muffler (DM) which is installed in the cylinder 3 to be connected to the discharge side of the valve assembly 8.
The suction muffler 10 as shown in FIG. 2A, comprises an inlet port 11 which is connected to the refrigerant suction channel SP (shown in FIG. 1) which penetrates the inner part of the casing 1 or the casing 1 itself, an outlet port 12 which is connected to the suction side of the valve assembly 8 to lead the refrigerant gas flown through the inlet port 11 to a compression space of the cylinder 3(shown in FIG. 1), first compartment 13 and second compartment 14 for dividing the inner volume between the inlet port 11 and the outlet port 12 to first, second and third extended spaces S1, S2 and S3, first passage pipe 15 for connecting the first extended space S1 and the second extended space S2 by penetrating the first compartment 13 vertically, second passage pipe 16 for connecting the second extended space S2 to the outlet port 12, and a resonance hole 17 for connecting the third extended space S3 to the outlet port 12 so that the second passage pipe 16 is formed penetrating the peripheral wall at a center of the second passage pipe 16 and forming a Helmholtz Reservoir together with the third extended space S3.
In FIG. 1, reference numeral 4A designates a stator, 18 designates an oil drain hole, C designates a support spring, O designates an oil feeder and SP designates a compressor suction channel.
A conventional reciprocating compressor having the above structure is operated as follows.
Firstly, power is supplied to the electric motor unit and the rotor 4B rotates by the interaction of the stator 4A and the rotor 4B.
The rotor 4B rotates together with the driving shaft 5 and the rotational motion is changed to a linear reciprocating motion by the connecting rod 6 which is combined to the eccentric part of the driving shaft 5 and the linear reciprocating motion is transmitted to the piston 7.
The piston 7 sucks, compresses and discharges the refrigerant gas performing a reciprocating motion in the cylinder 3 and pulsating pressure and noise occurred during the process, flow in the opposite direction of the flow direction of refrigerant gas and are attenuated by the suction muffler 10.
This operation will be described in more detail as follows.
In case of a suction stroke in which the piston 7 moves from a top dead point to a bottom dead point, the refrigerant gas filled in the second extended space S2 opens the suction valve (not shown). Then the refrigerant gas is sucked to the compression space of the cylinder 3 and at the same time, new refrigerant gas is flown to the second extended space S2 through the refrigerant inlet port 11, the first extended space S1 and the first passage pipe 15.
On the other hand, in case of a compression stroke in which the piston 7 moves from a bottom dead point to a top dead point, the discharge valve (reference numeral is not shown) is opened at the same time as the suction valve (reference numeral is not shown) is closed and the compressed gas is discharged to the discharge space DS of the head cover 9 through the discharge valve.
At this time, repeated pulsating pressure is occurred continuously in the suction muffler 10 and the head cover 9 in the repeating process of suction and discharge of the refrigerant gas.
This pulsating pressure having phase difference is transmitted through each channel of the suction muffler 10. However, consequently the pulsating pressure greatly decreases at the inlet port 11 and the refrigerant gas flows smoothly since the pulsating pressure is attenuated gradually and almost removed.
Meanwhile, the noise occurred during suction of the refrigerant gas is converted to a heat energy by diffusion and dissipation and attenuated passing through the respective passage pipes 15 and 16, and extended spaces S1 and S2, and at the same time, the noise having a certain frequency is attenuated by the Helmholtz""s Effect at the Helmholtz resonance portion which comprises a resonance hole of the second passage pipe 16 and the third extended space S3. Accordingly, the whole noise decreases.
However, in the above conventional suction muffler, the inlet port 11 which forms a suction channel, the first passage pipe 15, and the second passage pipe 16 are positioned in parallel to each other and accordingly, the refrigerant gas flows in zigzags.
Therefore, by the flow of the refrigerant gas in zigzags, a smooth flow of the refrigerant gas is interrupted and the refrigerant gas flown from the inlet port 11, the first passage pipe 15, and the second passage pipe 16 collides with the walls of the respective extended spaces S1, S2 and S3. Accordingly, the speed energy of the refrigerant gas is converted to a collision energy and thus to cause flow loss.
Also, in another conventional suction muffler as shown in FIG. 2B, first passage pipe 21 (inlet port in drawings) and second passage pipe 22 form a right angle each other, or in the other conventional suction muffler as shown in FIG. 2C, first passage pipe 31 is positioned on a straight line with the second passage pipe 32 thus to improve flow of refrigerant gas.
However, in the suction muffler shown in FIG. 2B, the refrigerant gas sucked through the first passage pipe 21 is collided in an extended space 23 and then flown to the second passage 22. Accordingly, flow loss by collision still remains.
On the other hand, in the suction muffler shown in FIG. 2C, the pulsation flow transmitted to the first passage pipe 31 in the operation of the compressor collides with the refrigerant gas sucked through the second passage pipe 32 and interrupts the flow of the refrigerant gas. Therefore, due to the decrease in amount of the sucked gas, efficiency of the compressor decreases.
Reference numeral 24 designates a resonance hole, 25 designates a resonance space, 33 designates a extended space, 34 and 36 designate resonance holes and 35 and 37 designate resonance spaces.
Therefore, an object of the present invention is to provide a muffler of a compressor which can minimize flow resistance of suction channel when sucking refrigerant gas and flow resistance of pulsation flow.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a muffler of a compressor, having an outlet end of a passage pipe at an inlet side and an inlet end of a passage pipe at an outlet side on the basis of suction direction of fluid connected together by an extended space, wherein an imaginary central line of flowing direction in the passage pipe at the inlet side and an imaginary central line of the flowing direction in the passage pipe at the outlet side are formed to have an angle of 40xcx9c50xc2x0.
There is also provided a muffler of a compressor, having an outlet end of a passage pipe at an inlet side and an inlet end of a passage pipe at an outlet side on the basis of suction direction of fluid connected together by an extended space, wherein a curved surface having a certain curvature is formed in the extended space between the outlet end of the passage pipe at the inlet side and the outlet end of the passage pipe at the outlet side.
There is also provided a muffler of a compressor, having an outlet end of a passage pipe at an inlet side and an inlet end of a passage pipe at a outlet side on the basis of suction direction of fluid connected together by an extended space, wherein an imaginary central line of flowing direction in the passage pipe at the inlet side and an imaginary central line of the flowing direction in the passage pipe at the outlet side are formed to have an angle of 40xcx9c50xc2x0 and a curved surface having a certain curvature is formed in the extended space between the outlet end of the passage pipe at the inlet side and the inlet end of the passage pipe at the outlet side.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.